There would be a single lander that would touch down on the flanks of a volcano, Mielikki Mons, which an infrared spectrometer on the Venus Express spacecraft has identified as a possible location of fresh lava flow.

The craft would make measurements during the descent with "temperature, pressure, dynamics and wind speed hardware, a tunable laser spectrometer to measure stable isotope ratios and a neutral mass spectrometer to measure gases." Cameras would take descent and landed images. A robotic arm would scrape aside the top layers of soil while a "a neutron-activated gamma ray spectrometer and a third spectrometer [presumably a laser-induced breakdown spectrometer ("LIBS")] would measure soil chemistry.

Pawel G., one of this blog's readers, sent me two links to sites the describe Russia's planetary ambitions. I don't read Russian (those Russian classes in college a few decades ago went to waste I guess). I believe that these are wish lists much as various scientific communities in the United States draw up lists of missions they'd like to see fly. I doubt that Russia has or will budget the funding for more than a few of these. If any you know differently, please let me know.

The first website, http://www.novosti-kosmonavtiki.ru/phpBB2/viewtopic.php?p=257249, per what I could gleam using Google translate, discusses a list of missions of which Phobos-Grunt and Venera-D I believe are approved (the former is largely built). Grunt in Russian reportedly means 'soil,' so the grunt missions below are probably sample return missions.

The second presentation, http://www.novosti-kosmonavtiki.ru/phpBB2/viewtopic.php?t=8434, appears to be from a conference and is partially in Russian and partially in English. This presentation lays out the engineering approach to enabling a number of missions. In this approach, standard modules such as in insertion module, a cruise module (also shown with landing legs, so perhaps the science platform module might be a better description), and a sample return module would be combined for different missions.

Editorial Thoughts:

It's good to see Russia returning to planetary exploration. The idea of modular spacecraft stacks is intriguing, and might be key to enabling a number of missions while holding down costs.

NASA CHOOSES THREE FINALISTS FOR FUTURE SPACE SCIENCE MISSION TO VENUS,
AN ASTEROID OR THE MOON

WASHINGTON -- NASA has selected three proposals as candidates for the
agency's next space venture to another celestial body in our solar
system. The final project selected in mid-2011 may provide a better
understanding of Earth's formation or perhaps the origin of life on
our planet.

The proposed missions would probe the atmosphere and crust of Venus;
return a piece of a near-Earth asteroid for analysis; or drop a
robotic lander into a basin at the moon's south pole to return lunar
rocks back to Earth for study.

NASA will select one proposal for full development after detailed
mission concept studies are completed and reviewed. The studies begin
during 2010, and the selected mission must be ready for launch no
later than Dec. 30, 2018. Mission cost, excluding the launch vehicle,
is limited to $650 million.

"These are projects that inspire and excite young scientists,
engineers and the public," said Ed Weiler, associate administrator
for the Science Mission Directorate at NASA Headquarters in
Washington. "These three proposals provide the best science value
among eight submitted to NASA this year."

Each proposal team initially will receive approximately $3.3 million
in 2010 to conduct a 12-month mission concept study that focuses on
implementation feasibility, cost, management and technical plans.
Studies also will include plans for educational outreach and small
business opportunities.

The selected proposals are:

The Surface and Atmosphere Geochemical Explorer, or SAGE, mission to
Venus would release a probe to descend through the planet's
atmosphere. During descent, instruments would conduct extensive
measurements of the atmosphere's composition and obtain
meteorological data. The probe then would land on the surface of
Venus, where its abrading tool would expose both a weathered and a
pristine surface area to measure its composition and mineralogy.
Scientists hope to understand the origin of Venus and why it is so
different from Earth. Larry Esposito of the University of Colorado in
Boulder, is the principal investigator.

The Origins Spectral Interpretation Resource Identification Security
Regolith Explorer spacecraft, called Osiris-Rex, would rendezvous and
orbit a primitive asteroid. After extensive measurements, instruments
would collect more than two ounces of material from the asteriod's
surface for return to Earth. The returned samples would help
scientists better undertand and answer long-held questions about the
formation of our solar system and the origin of complex molecules
necessary for life. Michael Drake, of the University of Arizona in
Tucson, is the principal investigator.

MoonRise: Lunar South Pole-Aitken Basin Sample Return Mission would
place a lander in a broad basin near the moon's south pole and return
approximately two pounds of lunar materials for study. This region of
the lunar surface is believed to harbor rocks excavated from the
moon's mantle. The samples would provide new insight into the early
history of the Earth-moon system. Bradley Jolliff, of Washington
University in St. Louis, is the principal investigator.

The proposals were submitted to NASA on July 31, 2009, in response to
the New Frontiers Program 2009 Announcement of Opportunity. New
Frontiers seeks to explore the solar system with frequent,
medium-class spacecraft missions that will conduct high-quality,
focused scientific investigations designed to enhance understanding
of the solar system.

The final selection will become the third mission in the program. New
Horizons, NASA's first New Frontiers mission, launched in 2006, will
fly by the Pluto-Charon system in 2014 then target another Kuiper
Belt object for study. The second mission, called Juno, is designed
to orbit Jupiter from pole to pole for the first time, conducting an
in-depth study of the giant planet's atmosphere and interior. It is
slated for launch in August 2011.

Editorial Thoughts:

All three of these missions have been proposed before (Osiris-Rex as a Discovery mission) and all three would provide excellent science. The final selection, I suspect, will come down to which provides the best combination of low risk within the budget. All three designs, I believe, are likely to have technical challenges, so I wouldn't want to handicap which is more likely to meet those criteria.

From a personal perspective, I favor the Venus mission because I think that understanding the other large terrestrial planet relates to questions that interest me more. But any of these would be excellent.

Monday, December 28, 2009

Steven Squyres, chair of the on-going planetary Decadal Survey, publishes letters every two months updating the planetary community on the status of the Survey. In the latest letter, he lists the approved list of missions that are undergoing study as possible recommendations. This is a shorter list than in my summary from the Survey update given at the AGU conference. It's not clear if some of the missions on the latter list were not approved or just haven't been considered yet.

A major focus of the Steering Group meeting was the latest set of mission study requests from the panels. These were based largely on white paper input, and a number of new studies were approved and initiated.

Three of the new studies are of the type known as "Rapid Mission Architecture" studies. These are high-level studies of overall mission architecture that we expect to take a few weeks. The purpose of these studies is to explore the trade space for a specific mission candidate, in order to identify a "point design" for a possible subsequent full mission study. The three new Rapid Mission Architecture studies are:

There are also two new full mission studies. These will be more time-consuming and labor-intensive, and are intended to take these mission concepts to the point where they are ready for a full independent cost estimate. The two new full mission studies are:

1) Jupiter-orbiting Io mission (JPL)
2) Ganymede mission (JPL)

In addition, three more mission concept studies have been identified that have already been done to a level of maturity such that an independent cost estimate should be possible. Those three mission concepts are:

Sunday, December 27, 2009

(This is a repost of an entry whose formatting became screwed up beyond my ability to fix.)

Ryan Anderson at The Martian Chronicles has been blogging about the science results reported at the AGU conference. I missed many of these sessions, and found his blogs to be crisp, comprehensive (of the major results), and well written. This conference is so vast that no one can go to all the planetary talks and posters, but his blog is a good start.

Saturday, December 26, 2009

I started this blog in October 2008 thinking that a few people probably had some interest in the planning of future planetary missions. Tonight, I ran the stats and discovered that from Christmas 2008 to Christmas 2009, this site had 11,730 unique visitors, far more than I had expected. (It's hard to tell how many of those people continue to follow the blog after the first visit. Many people follow blogs via readers, which are invisible to the tools that follow site hits.)

I want to thank everyone who have taken the time to follow these postings. The coming year promises to be an interesting one as the Decadal Survey makes its recommendations for the coming decade.

Thursday, December 24, 2009

A reader pointed out that the link I had for instrument costs (http://futureplanets.blogspot.com/2009/12/what-instruments-cost.html) pointed to a document that didn't have instrument costs. There were several reports on possible Mars Science Orbiter goals issued within a couple of years, and it seems I pointed to the wrong one. This is the correct link:

I'm on an informal discussion group that discusses future planetary missions. One of the members, Phil H. argued that the Mars sample return should be designed to cost, and he agreed to have his argument posted here. I'll let you evaluate his arguments and reach your own conclusions. This is an issue that has been debated by the planetary community for decades.

I always welcome thoughtful commentaries; please send me any that you might have.

I think that for Mars Sample Return to actually fly, NASA needs to design a mission "to cost." This would be similar to the approach that the Solar Probe team was forced to follow. When it became apparent that the Classic Solar Probe mission, including Jupiter flyby, was too expensive to get approved ($1.1 Billion), they went to Plan B. This Plan B is called Solar Probe Plus and it was designed to come in under a cost ceiling of $750 Million. Solar Probe Plus is now the design of choice and will be launched in 2015-2017.
This was similar to the Pluto Express case. When JPL could not bring in a proposal for under $1 Billion, it was put out to bid for $650 million, as I recall. The APL proposal won. As a result, the New Horizons probe is now on its way to Pluto.
Recently, there have been several proposals for low-cost, low-risk MSR missions. I have attached a couple of these reports. What these missions have in common is a realization that the first MSR needs to be as simple as possible in order to be approved and to succeed.
I refer you to the end of the BASALT mission proposal (by J.Jones?), in which it is stated that "To make sample return viable, we must devise a low-risk, AFFORDABLE mission." I agree and believe that is the only way that an MSR mission will ever get approved.
I refer you to McKay's proposal which like Jones' concept, is simple. McKay also adds the further risk-reduction effort of sterilization of the returned samples. With sterilization, NASA can avoid the expense of a Receiving Lab designed to reduce the risk of an Andromeda Strain situation. However, as McKay points out, even with sterilization, biologically significant data can still be derived from the returned samples.
Another insightful comment from p.10 of McKay's MSR proposal - "Don't try to solve the 'life on Mars' question in a single mission. The VIKING MISTAKE." This is advice that NASA should heed.
By contrast, recent MEPAG reports continue to advocate "Battlestar Galactica" schemes for MSR. Perhaps, someday these "dream" MSR missions will be flown. However, in my opinion, the first one or two Sample Return missions need to simplify, simplify. As seen with the MSL Rover, complexity grows as a spacecraft progresses from Phase A to Phase B. It is better to start off with a simple design for MSR, since it is a given that, for it to fly successfully, it will need to be "tweaked" by the engineers. This will add some complexity and cost. However, if one starts with "Battlestar Galactica," then one has no margin for growth in cost, complexity or risk.
Mars Sample Return will require several new technologies. Each of these adds to the complexity and cost of the mission. In my opinion, it would be better to limit the number of "miracles" necessary to fly the first MSR. There are several "miracles" that must be developed in order for MSR to fly, e.g., Mars Ascent Vehicle (MAV), Earth Return Vehicle (ERV), Mars Orbit Rendezvous and Docking (or ISRU for a direct ascent vehicle). If we can fly a simple "groundbreaking" MSR mission, such as described by Jones and McKay, then we can not avoid the costs of developing those steps. However, if we can avoid, in the First MSR mission, extra costs such as a biologically secure receiving lab, or fetch rovers, or complicated sampling procedures, then perhaps we can afford MSR.
If NASA does approve a cost-capped MSR, then I believe that the next step should be to put it out for bid, as is done with Discovery and New frontiers missions, and as was done for the Pluto Express mission, as described above. There are other capable entities out there, such as APL, NASA Goddard and Lockheed-Martin, that can bid for these missions. With JPL's monopoly at an end, perhaps we will see the forces of the marketplace bring the costs of Mars missions down. This would go along with my intial comments that the MSR should be built to "cost." This might sound radical, but that is exactly the way that business is conducted in the Discovery and New Frontiers missions.
One more note on how simplifying MSR might impact the MAX-C Mars Rover. There is talk now of the need to sterilize some or all of the MAX-C Rover in order not to contaminate any cached Mars samples. This would occur if MAX-C becomes part of an MSR mission. If, however, those Martian samples are themselves sterilized, then this would reduce the cost, and decrease the risk, of the MAX-C Rover.
I want to see MSR occur, and I want that to happen soon. I believe that with a simple mission design, that might come to pass.

Sunday, December 20, 2009

The American Geophysics Union's Fall meeting is really an assortment of scientific conferences. I go for my professional interests, the remote sensing of vegetation structure. Once there, I always stay an extra day to take in sessions on planetary exploration. This year, future planetary exploration was an added theme in support of the ongoing Decadal Survey. Many of the posters and presentations covered topics already discussed on this blog. A few were new, and I'll summarize these over 2 - 3 blog entries.

An entire session was devoted to updating the planetary community on the progress being made by the focus panels. Steve Squyers, chairman of the overall Survey, gave an overview of the process. A Steering Group oversees the entire process and has two responsibilities. The first is to look at issues that cut across all planetary programs. At the last meeting (notes and presentations have yet to be posted), it looked at plans for the Deep Space Network, the plutonium supply (no good new there), and launch vehicle costs (rising rapidly, reducing money for spacecraft and science). The next meeting will look at technology readiness. The second responsibility of the Steering Group will be to look at the prioritized list of missions from each focus group to select a final list of missions to recommend to NASA. The focus groups are scheduled to deliver their recommendations this coming May. The Steering Group will publish a draft recommendation in the second half of 2011 with a final report in the first half of 2012.

A member (usually the chair) of each focus group delivered a short summary of the group's key scientific questions and a list of missions it is examining for possible recommendation to the Steering Group. Missions that are not well defined are assigned to the Rapid Mission Assessment (RMA) process to provide a baseline definition. Missions that are better defined, either from previous work or an RMA, can be selected for an independent cost assessment. All recommended missions must go through the independent cost assessment.

For the rest of this entry, I'll list the missions that each group is assessing:

Inner Planets (Mercury, Venus, the moon): Lunar south pole sample return, Venus in situ surface explorer (VISE), Mercury lander, lunar seismic network; two other missions are likely to be added: a lunar volatiles mission and a Venus climate mission. It wasn't clear which missions were in the RMA versus cost assessment stages.

Mars: The candidate missions for Mars have been well studied so the list is familiar to anyone following this blog: Trace Gas Orbiter (this mission may be grandfathered in as a committed mission by the publication of the Decadal Survey report), the MAX-C rover that would be the first element of a three part Mars sample return and that would collect and cache samples, a Mars network mission focusing on geophysics with some meteorological studies, and the remainder of the Mars sample return missions.

Giant Planets (not including their moons): Missions here are not well defined, so the proposals are in the RMA stage: A Neptune/Triton/Kuiper Belt Object flyby mission with options for a Neptune entry probe and/or nano probes that would study Neptune's magnetosphere from multiple locations; a Uranus orbiter, and a Saturn probe mission. One issue missions to giant planet and their moons would share may be a dependency on ASRG power supplies as plutonium supplies dwindle. These power sources are rated for 17 years of life after assembly. By the time launch arrives, 14 years of life are left. Missions to the outer solar system can often take as long as 10 years or more to arrive at their destination, leaving only a handful of years for study.

Primitive Bodies: This presentation did not list a selection of missions because missions to every possible class of targets (Near Earth, main belt, Trojan, and Centaur asteroids and comets) are in competition for the current New Frontiers selection. Presumably the best ideas not selected from the competition will be put forward as proposed missions for the Decadal Survey. (Whichever mission is selected will be grandfathered in as a committed mission and would be outside the scope of the Decadal Survey process.)

Saturday, December 19, 2009

In January or Feburary, the President will propose a new budget for FY2011 (which starts in October 2010) for the federal government, including NASA. The planetary program is too tiny a fraction of the budget to cause speculation prior to release. Early indications seem to be a tension between reducing deficits and a small ($1B increase to the FY10 ~$18B budget) increase for the manned spaceflight program and Earth observation missions (see Obama Backs New Launcher and Bigger NASA Budget and An extra billion for NASA in FY11?)

My take on this for the planetary program is that extra money for NASA may reduce pressures to raid the planetary program to fund the manned and Earth observation programs. We may see the planetary budget hold steady for the coming year. An alternative would be that all NASA programs except the manned and Earth observation programs will be cut 5% (to match the general cut being asked of all federal agencies) with the savings applied to those two programs.

I'll begin posting summaries from the AGU meeting tomorrow (after seeing Avatar, which I hope lives up to its hype).

Thursday, December 17, 2009

Space.com has an article on the current status of the Mars Science Laboratory, 'Curiosity.' The good news is that most technical and budget concerns have been resolved and no longer threaten the launch schedule or budget. However, NASA is still trying to determine if substandard titanium parts possibly delivered by a contractor could fail. Depending on where any substandard titanium was used, it could be the cause of another launch delay.

Also, I'm at the AGU conference. For this afternoon and tomorrow morning, several sessions focus on future missions and updates on the Decadal Survey process. Look for an update Friday night or Saturday morning.

Sunday, December 13, 2009

NASA has released a draft of its Announcement of Opportunity (AO) for the next Discovery mission. Release of the final AO typically follows in a few weeks to a handful of months based on comments from the proposer community on the draft.

This promises to be a rich set of proposed missions. Possible missions that have been discussed publicly and described in this blog include:

There are likely to be dozens of other ideas proposed, especially since the cost cap has been raised by not including the launch vehicle in the Principle Investigator's (PI) budget and by the possibility of using a plutonium power source (the ASRG) at no cost to the PI.

Personally, I can't find a favorite among the concepts that have been discussed publicly. All are excellent, and I expect that many that haven't been discussed would be equally good.

The National Aeronautics and Space Administration (NASA) Science Mission Directorate (SMD) is releasing this Announcement of Opportunity (AO) to solicit Principal Investigator (PI) led planetary science investigations for the Discovery Program.

NASA expects to select one Discovery mission to proceed into Phase B (or an extended Phase A) and subsequent mission phases. The selected mission’s primary launch date shall be no later than the end of calendar year 2016.

One of NASA’s strategic goals is to “Advance scientific knowledge of the origin and history of the solar system, the potential for life elsewhere, and the hazards and resources present as humans explore space...” The NASA Science Mission Directorate (SMD) is addressing this strategic goal by conducting a program of planetary science designed to answer the following science questions:

How did the Sun’s family of planets and minor bodies originate?

How did the Solar System evolve to its current diverse state?

What are the characteristics of the solar system that lead to the origin of life?

How did life begin and evolve on Earth and has it evolved elsewhere in the solar system?

What are the hazards and resources in the solar system environment that will affect the extension of human presence in space?

Investigations may target any body in the Solar System, including Mars and Earth’s Moon, but excluding the Earth and Sun, in order to advance the objectives outlined [above]... Investigations focused on Mars are allowed (Section 2.2)... Investigations of extra-solar planets are not solicited in this AO.

The cap on the PI-Managed Mission Cost for a Discovery mission is $425M in Fiscal Year (FY) 2010 dollars, not including the cost of the standard launch vehicle (LV) or any contributions (Section 4.3.1 and Section 5.6.1). The cap may be increased through the optional use of specific NASA-developed technologies.

The cost of standard launch services is not included within the cap on the PI-Managed Mission Cost, but mission-unique launch services and the differential cost of more capable LVs than the standard LV will be included in the PI-Managed Cost.

The minimum reserve level of 25% is now assessed against the Phase A-E cost rather than the Phase A-D cost.

Proposal of investigations enabled by the use of Advanced Stirling Radioisotope Generators (ASRGs) is allowed (Section 5.9.3). ASRGs are provided as Government Furnished Equipment (GFE).

New propulsion technology has been developed by NASA and is available for infusion into Discovery missions [an advanced ion propulsion engine (NEXT), Advanced Material Bi-propellant Rocket (AMBR) and aerocapture].

This AO solicits flight missions, not technology development projects. Proposed investigations are generally expected to have mature technologies, specifically all technologies at a Technology Readiness Level (TRL) of 6 or higher ... Proposals with a limited number of less mature technologies are permitted, as long as they contain a plan for maturing all technologies to TRL 6.

Proposed investigations will be evaluated and selected through a two-step competitive process. Step 1 is the solicitation, submission, evaluation, and selection of proposals prepared in response to this AO. As the outcome of Step 1, NASA intends to select approximately three Step 1 proposals and issue awards (provide funding to NASA Centers and the Jet Propulsion Laboratory (JPL), award contracts to non-NASA institutions, or utilize other funding vehicles, as applicable) to the selected proposers to conduct Phase A concept studies and submit Concept Study Reports to NASA. Step 2 is the preparation, submission, evaluation, and continuation decision (downselection) of the Concept Study Reports. As the outcome of Step 2, NASA intends to continue a single investigation into the subsequent phases of mission development for flight and operations.

Saturday, December 12, 2009

Space News has an article (Russia Withholding Plutonium NASA Needs for Deep Space Exploration) stating that Russia is withholding promised plutonium-238 for NASA missions. This follows Congress' decision not to start the process for new production of plutonium-238 in the United States for the current fiscal year. According to the article, Russia wants to negotiate a new contract, but no reason is given. (It may be that the Russians realize that without U.S. production capabilities, NASA can be forced to pay considerably more for plutonium than the current contract calls for.)

The article goes on to state that the Jupiter Europa Orbiter cannot be flown without (1) the Russian plutonium, (2) a restart of U.S. production, or (3) use of the unproven ASRG power sources. Either of the latter two cases would slip launch of the mission past 2020.

The article states, "Jim Green, NASA’s director of planetary science, recently told scientists drafting the U.S. space agency’s next 10-year plan for robotic exploration of the solar system that the era of plutonium-powered missions could be coming to an end."

Friday, December 11, 2009

This entry continues Bruce Moomaw's description of the new plans for a Mars Sample Return. The first part can be found here.

Background: At the last meeting of the Mars panel of the Decadal Survey, a detailed plan for conducting a Mars sample return. The slides have not been posted, but Bruce Moomaw acquired a copy and wrote the entry below. If you are interested you can watch the presentation, although video and audio drops out fairly frequently and at some key points. Go to http://nasa-nai.na6.acrobat.com/p26625026/ and fast forward through the first three presentations (although the third is an excellent rational for doing a sample return).

The second theme that turns up in Fuk Li's recent presentation to the Mars panel of the Solar System Decadal Survey project regarding the design of a Mars sample return (MSR) mission is how much preliminary research has already been done on the possible design for it -- and the extent to which these efforts have already led to preliminary strawman designs for its components. As Dr. Li says, some desirable technologies -- working rovers, the MSL's "Skycrane" landing system, aerobraking into a low circular Mars orbit -- have already been developed, and that while "we do have remaining technical challenges, I believe we have identified them and that we have defined technology plans" to deal with them. A few examples:

(1) Li regards development of the Mars Ascent Vehicle as the single most difficult remaining task associated with the MSR mission: "We have not built and flown this rocket", and his chart rated its technical development difficulty as "high". However, repeated studies since 2001-02 have already done a surprising amount of preliminary work on its design; three industry studies converged on a strawman design for it which was approved as feasible by JPL's "Team X" group and the Marshall Space Flight Center, and this has been confirmed by other studies since. Li still stated that its final development will likely take another seven or so years: three years to recheck various possible alternative designs (some perhaps using liquid rather than solid fuel) before settling conclusively on a final one, and four years to actually develop the chosen system and flight-test it in Earth's upper atmosphere.

The strawman concept is a slim two-stage rocket, weighing about 300 kg (including a 40% margin), and standing about 2.5 meters high, with its two stages using already long-developed STAR solid motors and liquid-fueled attitude thrusters. During its stay on the Martian surface it would be encased in a slim heated "igloo" to protect its propellant from the effects of Mars' cold. It would lie on its side, allowing the mechanical arm on the Lander to remove the cylindrical sample container from the returning sample "Fetch Rover" and load it into the spherical Orbiting Sample Canister located on the MAV's top; and then it would be elevated into a vertical position to take off out of the opened top of the igloo.

(2) The second-most difficult remaining technical challenge for the Mars sample return mission is the development of its anti-contamination systems, to avoid both "forward contamination" of Mars (especially the sampled material) by Earth contaminants on the landed vehicles, and "back contamination" of Earth by Martian material that is on the surface of the sample containers or has been released from a ruptured container. Li's chart rated the likely technical difficulty of both phases as being in the "medium" range. He stated that forward contamination will be avoided not by the difficult technique of sterilizing each entire landed vehicle, but by the technique used on the Phoenix Mars lander: sterilizing all the components on the MAX-C sample collecting rover, the Fetch Rover, and the sample-return Lander that are likely to come into contact with the sampled materials, sealing them after "clean assembly" inside "biobarriers" that will be removed after landing, and using less rigorous clean-assembly techniques to minimize the number of microbes or organic contaminants on the rest of the landed spacecraft.

Unfortunately, Li was vague on the likely techniques that would be used to minimize the risk of back-contamination of Earth by Martian material. He did note that precautions against this will likely be built into both the sample-return Lander and Orbiter, and that the sample container removed from the Fetch Rover will be implanted in the Orbiting Sample Canister using a "double-seal" technique.

(3) According to Li, a surprising amount of promising work has already been done on the seemingly difficult task of having the sample-return Orbiter locate and rendezvous with the tiny Orbiting Sample Canister that will be launched back into orbit around Mars from the planet's surface by the Mars Ascent Vehicle, and capture the Canister so that it can be loaded into the heat-shielded Earth Entry Vehicle capsule carried on the Orbiter. The current plan is, in fact, to use cameras on the Orbiter to locate the Canister at a distance of up to 10,000 km away -- with the first-stage development of such a camera already carried on the Mars Reconnaissance Orbiter -- although the Canister will carry a simple radio beacon as a backup for long-range tracking. After carrying out an automated rendezvous, the Orbiter will "dock" with the round Canister by scooping it up in a conical retrieval basket and funnelling it into the EEV capsule. Li says that many of the systems and computer algorithms needed to carry out such a complex operation have already been tested to a considerable degree in Earth orbit by the DARPA military research agency's "Orbital Express" mission that carried out repeated automated rendezvous and docking between two unmanned Earth satellites in 2007. In a chart of current estimates of the difficulties likely to be encountered in developing various technologies for the sample-return mission, unmanned rendezvous and retrieval was ranked in the "low to medium" level.

(4) There is great confidence in the existing design of the Earth Entry Capsule, which underwent drop tests as far back as 2001. It would not use a parachute, but would instead nestle the OS canister inside a thick layer of crushable material that would protect it against the full-speed crash of the EEV onto Earth's surface -- a design that both saves weight and actually improves protection from any rupture of the sample container by avoiding any risk of parachute failure.

(5) The Returned Sample Handling Facility that would store the samples for protection and study -- as well as appraising them for possible hazards prior to releasing them to outside facilities for further study -- has already undergone competitive engineering studies by three different firms in 2003. It would operate at a "Biosafety Level" of BSL-4, like some existing facilities, and apparently there are no great difficulties likely in designing of building it -- although the sooner the process is begun the better.

(6) A few other notes:

(A) All three of the spacecraft involved in the current design of the sample-return mission -- the MAX-C rover, the Orbiter and the Sample-Return Lander -- would be launched on Atlas V 551 boosters. (An error in my previous report: the SR Lander, under the current design, would be launched in 2024 -- only two years after the Orbiter -- rather than in 2026. In any case, the MAX-C rover would almost certainly be dead by the time the Fetch Rover shows up, which will not stop the latter from retrieving its container of cached samples.)

(B) The MAX-C rover, the Fetch Rover and the Lander platform would all be powered by solar arrays, unlike the Mars Science Laboratory.

(C) The plan is to improve the computer algorithms for driving the MAX-C and Fetch Rovers beyond those on the Mars Science Laboratory, allowing them to drive a minimum of 200 meters per day instead of just 65 meters minimum. This would be done by allowing the rovers to process their images for navigation purposes while they were actually moving, rather than forcing them to stop at intervals for such processing.

(D) Four studies conducted this year by different industrial groups instill confidence that a reliable way can be found for the MAX-C rover to extract rock cores and cache them in its sample container. The tentative plan is for it to collect 30 10-gram rock cores, probably from three to five overall locations during its drive.

Finally, there is the burning question of the cost of this mission. Dr. Li reported the results of three recent mission cost estimates, all of them in 2015 dollars. Two were provided by JPL's Team X group and the the independent Aerospace Corporation, both of which tried to estimate costs down to about 100 million dollars. The third estimate came from studies by analogy of the different main components of this mission with earlier spacecraft, such as MRO and MSL (although all the cost estimates made an attempt to incorporate the unhappy recent experiences with serious cost overruns on the MSL). As one might expect, this third estimate was a lot rougher, calibrated only down to about a half-billion dollars.

Team X and the Aerospace Corp. both estimated the likely cost of MAX-C at $2.1 billion; the study by analogy pegged it at about $2 billion.

Team X and Aerospace Corp. estimated the orbiter at $1.1 to 1.3 billion; the analogy estimate was about $1.5 billion.

Team X and Aerospace Corp. estimated the sample-return lander at $2.3 to 2.4 billion; the analogy estimate was a good deal higher at $3 billion.

Finally, separate estimates of the cost of the Sample Handling Facility pegged it at about $300 to 500 million.

The sum-total estimates by Team X and Aerospace Corp. estimated the total cost of this mission at $5.9 to $6.2 billion; the rougher (but perhaps more trustworthy) estimate by mission analogy put it a good deal higher at about $7 billion. Repeats of such a multi-part mission would cost a good deal less, since so much of the first mission's cost would consist of its initial design and development -- but it's clear that we are talking about the sort of thing that cannot be done more than about once per decade, and which during that decade would be likely to completely consume the costs of the Mars Exploration Program -- something that must be taken into account when deciding whether to go ahead and ask Congress to approve this ambitious mission.

Tuesday, December 8, 2009

At the last meeting of the Mars panel of the Decadal Survey, a detailed plan for conducting a Mars sample return. The slides have not been posted, but Bruce Moomaw acquired a copy and wrote the entry below. If you are interested you can watch the presentation, although video and audio drops out fairly frequently and at some key points. Go to http://nasa-nai.na6.acrobat.com/p26625026/ and fast forward through the first three presentations (although the third is an excellent rational for doing a sample return).

Bruce's entry follows:

At the second meeting of the Mars Panel of the current Decadal Survey project on Nov. 4 to 6, JPL's Mars Exploration Program manager Fuk Li described the current status of studies of the design for a Mars sample return (MSR) mission. Two themes stood out, which I'll describe in two separate entries.

The first is the recent change in the favored design for the mission. Previously it was conceived as consisting of two launches at an interval of about four years. The first would be an orbiter, the second a lander. The lander spacecraft -- besides the underlying platform -- would consist of two components. One would be a Mars Ascent Vehicle capable of launching a small canister containing about half a kilogram of Mars samples into a low orbit around Mars, after which the orbiter spacecraft would carry out an automatic rendezvous with the canister, capture it, and then blast itself out of Mars orbit and back to Earth to fly by our planet and drop off an Earth return capsule carrying the canister. The other main component of the sample-return lander would be a long-range rover capable of using onboard instruments to analyze the Martian surface and identify promising sites for sample collection, and then drill up small rock cores that would be cached by the rover in a collection container. The rover would then drive all the way back to the main lander and load the sample container into the canister on top of the Mars Ascent Vehicle, which could then launch itself.

However, Dr. Li reported that there is now a consensus developing -- which he himself has come to strongly agree with -- for the Mars sample return mission to be split not into two component launches, but into three. The sample-collection rover would be launched separately first -- preferably in 2018 -- as the "Mars Astrobiology Explorer and Cacher" (MAX-C). This 300-kg rover would drive as much as 20 km across the surface during a lifetime of at least 500 Sols (Martian days), carrying out its analyses and sample collection, and would end up back in the center of its small landing ellipse (with a radius of about 6 km).

Four years later the orbiter would be launched, and then four years after that the lander would be launched. This lander, however, would instead carry a smaller, simpler "Fetch Rover" -- a bit smaller than the current Mars Exploration Rovers (around 155 kg) and somewhat simpler in overall design, but designed to drive faster and farther (a minimum of 12 km). Its sole function would be to hustle across the surface to the MAX-C rover, retrieve its sample container with an arm simpler than that on MAX-C, and return directly with the container to the lander -- which would have been targeted to land as close as possible to the center of the MAX-C landing ellipse. (The fact that it too might land as much as 6 km off target explains the need for a 12-km total driving capability for the Fetch Rover.) The rest of the mission would follow in the same way as the two-component mission design.

Li explained the multiple reasons for the design change. To begin with, it should be kept in mind that the rover intended for the two-component version of MSR would need virtually all the same instruments as MAX-C in order to identify good collection sites for its small collection of precious samples. Why does the new mission design fly this rover separately?

(1) The original mission design, after landing on Mars, had to work against the clock. As Li said, "The Martian surface environment is not very friendly" -- particularly to the Mars Ascent Vehicle, with its large propellant supply that may be sensitive to Mars' low surface temperatures -- "and we do not want to wait a long time for the rover to collect a sample." The new design allows MAX-C to explore a wide range of Martian surface features and carry out its sampling operations in a completely leisurely, scientifically well-designed way over a period of 17 months. By contrast, the Fetch Rover is planned to carry out its sample-retrieval round trip and return to the lander in only about three months, allowing the MAV to blast off from the surface after that short period (although the lander and MAV will be designed to operate reliably on the surface for up to 12 months, allowing a long safety margin).

(2) The new MSR lander, with its simpler rover, is lighter-weight -- lightweight enough that it can be carried to the surface by the same landing system (heatshield, parachute and "Skycrane") used by the 2011 Mars Science Laboratory and MAX-C. "The main thing I learned from MSL," Li says, "is that developing the Entry, Descent and Landing system is a major big deal. The technical challenges and money needed are just painful. We should capitalize on what we've already developed." MSL's EDL system can land a payload of about 1000 kg on the Martian surface -- and if the sample-return lander carries the smaller Fetch Rover, the total mass of the lander (with a safety margin of 40%) is indeed estimated to be about 1000 kg. But if the lander carries the heavier MAX-C type rover, its total mass could end up at about 1200 kg -- requiring a major new development effort for a new landing system.

(3) The new sample-return mission design, by spreading out its components over time, avoids much concentration of both technical problem-solving effort and spending at one point in time.

(4) The new plan has more flexibility to deal with problems. If MAX-C finds out that its selected landing site is less scientifically interesting than expected and would serve as a poor place from which to return samples, a second MAX-C can be launched and the sample-return orbiter and lander can be simply delayed. Putting the MAX-C rover on the actual sample-return lander would allow no such flexibility in choosing another sampling site. (Incidentally, the arm used by the sample-return lander to remove the sample container from the Fetch Rover and load it into the MAV's sample canister for launch can also be used to collect an emergency contingency sample of rock fragments and soil from the lander's immediate vicinity if the Fetch Rover fails to return with its sample.)

In the second part of this report, I'll describe the second theme that struck me about Li's presentation -- namely, the rather surprising extent to which design and development work for this mission is already underway and has led to a detailed preliminary design.

Saturday, December 5, 2009

In 2007, a science working team published a report on possible science goals for a twenty-teens Mars orbiter and possible small lander. In that report, they discussed a number instruments and their estimated costs. This is the only place where I have seen costs listed for such a wide range of instrument types. The goal of the study was to narrow down goals and instruments to a manageable cost. The result was a proposal for the Mars Trace Gas orbiter, which is now scheduled as an ESA/NASA mission for launch in 2016. At a minimum, that mission would fly the first three instruments on the list for a total instrument cost of ~$71M based on the numbers in the report. There is a strong desire to add a high resolution imager with an instrument cost of $25-45M plus additional costs in the spacecraft.

A couple of caveats. These costs are rough estimates; costs can go up or down by adding or removing capabilities. Also, these costs are likely in 2006 dollars; they likely will rise substantially with a decade's inflation.

Still, I found this list useful in understanding some of the trade offs for mission planning. The saddest trade off I know of was the deletion of the magnetometer from the DAWN asteroid mission when that mission had cost overruns. Theories suggest that the Ceres asteroid may have a subterranean ocean. The magnetometer would have told us by measuring changes in the solar magnetosphere that would be caused by such an ocean. (This was the method used by the Galileo spacecraft to detect oceans in the Galilean moons.) Now, it is probably at least decades before we will know for sure.

$12M/10kg: Thermal IR or “Lite” spectrometer system - Measure atmospheric dust and ice; could also do spectral mapping of surface composition depending on design (and cost)

$45M/85kg: “HiRISE” Class Imager (HCI) - High resolution imaging of surface at around 30 cm/pixel; would largely be a relight of the highly successful Mars Reconnaissance Orbiter HiRISE camera (which keeps the costs down). Any high resolution camera adds other costs to the spacecraft to provide accurate pointing, an ultrastable platform, data storage, and communications.

Wednesday, December 2, 2009

I'm on vacation with only occasional internet connectivity for the next two weeks. I may post an entry or two, but posts will be erratic. The following week, I will be at the American Geophysical Union conference, where proposals for missions for the Decadal Survey are a major topic. I'll attend and report on as many of those sessions as my real job allows.

Sunday, November 29, 2009

Cassini's surprise discovery of active plumes on Enceladus has made that moon a priority target for future exploration. The key question is whether their is an internal ocean that might -- like an internal ocean might within Europa -- harbor life. Even if Enceladus turns out to be lifeless, the existence of the plumes provides an inexpensive opportunity to sample the interior of an ice world.

Two Decadal Survey White Papers address science goals for future Enceladus exploration. The first, The Case for Enceladus Science, lays out the key scientific questions that future missions would address. If the Saturn Titan System flagship mission (~$3B) eventually flies, these questions will guide the planning of its Enceladus encounters. However, a flagship mission will not arrive at Saturn for at least another 15 to 20 years. Several of the authors of the science paper contributed a second paper, The Case for an Enceladus New Frontiers Mission to propose a mission that might launch in the coming decade. (New Frontier missions cost ~$650M.)

This mission would use solar power and batteries to avoid the costs of a plutonium power supply. Just four instruments would be flown:

"Mid-IR Thermal Instrument (MIRTI): The mid-infrared thermal mapper measures temperatures in the vent region, and can search for other regions on Enceladus that may be warmer than their surrounding areas. [This instrument would have both finer spatial and spectral resolution than Cassini]

"Ice Penetrating Radar (IPR): An ice penetrating radar system provides the best single measurement to determine Enceladus’ sub-surface structure, and unlike direct seismometry, does not involve touching the surface with its implications for planetary protection. [Cassini lacks this instrument]

"Enceladus Mass Spectrometer (EMS): Thus, to study all biologically interesting amino acids, while also studying bulk composition and high-order hydrocarbons, requires a mass range up to a minimum of 300 Daltons, with a mass resolution (m/Dm) sufficient to resolve molecular isotopes (m/Dm of 500). [Cassini's mass spectrometer measures only to 100 Daltons; a Dalton is another term for an atomic mass unit.]

"Imaging camera for Enceladus (ICE): The imager is a multi-spectral camera, capable of pushbroom imaging and high spatial resolution (5 m) to resolve the polar vents and other surface structures. [Resolution would be as fine as 5 meters.]

"Gravity Experiment: While not strictly a science instrument per se, it is highly desirable to further refine our knowledge of the Enceladus gravity field by performing multiple gravity passes. Passes at different sub-spacecraft latitudes will help constrain the interior structure."

The White Paper goes on to specify a number of mission requirements to fulfill the science goals. For example, the Enceladus Observer (to give this mission a name) would need at least 12 enounters at 100 - 200 kim altitude at various latititudes including both poles and the equator to determine core size and crust thickness. Pointing accuracy of the cameras would need to be 2 mrads to accomplish the imaging goals. Several flights through the plumes would be required.

After a 9.4 year flight to Saturn, the mission begins with four Titan encounters that set up the Enceladus encounters, which would typically occur at 4 km per second every 6.85 days.
Editorial Thoughts: I suspect that many of the readers of this blog imagine missions they would like to see fly. I'm no exception, and this is a mission I would like to see fly -- with a few modest enhancements. First, I'd like to see a near IR imager added that would be optimized to image Titan's surface through the spectral windows in it's clouds. And second, I would enhance the mission's satellite tour.

For the latter, I would include more Titan enounters to study its surface and upper atmosphere. (The White Paper states, "Titan science could also be accomplished with a spacecraft studying Enceladus, during many Titan flybys.") Then there would be a series of Enceladus encounters to fulfill the core Enceladus science much like those outlined in the White Paper. An extended mission could significantly enhance the science return. New astrodynamics studies have found that two years of encounters with Rhea, Dione, and Tethys would lower the Enceladus encounter speeds to ~1 km per second for around 50 encounters per year. Encounters with the other moons of Titan with this instrument set would allow comparative studies among the medium sized moons of Saturn. It's possible that the mission could end with the spacecraft entering orbit around Enceladus, again thanks to astrodynamic methods developed in the last few years.

And while I'm day dreaming, I'd like to see the mission enhanced to the small Flagship class (~$1B) by carrying a Titan lake lander that might be supplied by ESA. While I understand why Jupiter-Europa were prioritized over Saturn-Titan-Enceladus for the coming decade (technology readiness), I would like to see both an observer-class orbiter and a lake lander fly in the next decade. Twenty years is too long too wait.

Costs from the mission presentation. 2006 costs were those from a 2006 Mars Scout proposal that were judged to be too low

As with many missions, there are some unique aspects to this mission. First, there are two nearly identical spacecraft, so there are dollars for extra parts purchases. However, the nearly identical designs allows the design and testing dollars to be shared across both spacecraft. I've read that the cost of a second nearly identical craft is around an additional 60%. (Sometimes I've seen lower figures, but those seem to be for missions that have hot, flight ready spares so duplicate systems and even entire craft are already figured into the base mission costs.)

The MACO mission proposed to fly just three instruments, resulting in fairly low instrument costs. (I've seen estimates for individual instruments easily top the figure for this mission.) This mission also has relatively low data rates and moderate pointing costs. If a high resolution camera were to be added, costs would likely increase significantly to provide the spacecraft stability and aiming to point the camera accurately. A more capable data storage and communications system would be needed to handle the much larger data stream.

About Me

You can contact me at futureplanets1@gmail.com with any questions or comments.
I have followed planetary exploration since I opened my newspaper in 1976 and saw the first photo from the surface of Mars. The challenges of conceiving and designing planetary missions has always fascinated me. I don't have any formal tie to NASA or planetary exploration (although I use data from NASA's Earth science missions in my professional work as an ecologist).
Corrections and additions always welcome.